This invention relates to a supported metallocene catalyst system for the high yield synthesis of polyolefins, to methods of preparation of the catalyst system, to polymerization processes which use the catalyst system and to polyolefin polymers produced by the polymerization processes.
Recently there have been a number of advances in the production of polyolefin copolymers due to the introduction of metallocene catalysts. Metallocene catalysts offer a number of advantages including improved activity compared to traditional Ziegler catalysts under a given set of conditions. Also, metallocene catalysts are often described as being single-site in nature. Because of this single-site nature, the polyolefins produced with these catalysts are often very uniform in their molecular structure.
In order for metallocene catalysts to be commercially useful as supported catalysts in a gas phase, solution or slurry process, the catalysts employed preferably are highly active. High productivity of the catalyst in a polymerization processes is desired to reduce catalyst costs and to avoid the expense of catalyst residue removal procedures. Thus, the catalyst residue in the polymer must be low enough that it can be left in the polymer without causing any undue problems to either the resin manufacturer, or to a party fabricating articles from the resin, or to an ultimate user of such fabricated articles. When a highly active catalyst is used in a gas phase, solution or slurry process, the transition metal content of the polymer should be on the order of less than 1 part per million (ppm) of transition metal at a productivity level of greater than 1,000,000 pounds of polymer per pound of transition metal, One of the features of a gas phase polymerization reactor is that the gas velocity in the reactor is limited to prevent excess carry-over of the solid particles from the fluid bed, which would happen if the velocity is set too high. If the gas velocity is set too low, reactor fouling may occur due to fallout of polymer from the bed. Since the gas velocity is limited, the amount of heat which can be removed when operating at a given set of conditions is also limited. The limitations on heat removal place limitations on the rate of productivity for a given reactor. Attempts at improving the productivity of a gas phase reactor by increasing the catalyst feed rate will often not be met with success because of the heat removal limitations of the reactor.
A major improvement in reactor output and a partial solution to the heat removal limitations is described in U.S. Pat. Nos. 4,543,399, 5,352,749, EP 89691, WO 94/25495 and WO 94/28032, which are hereby incorporated by reference, where a volatile liquid is fed to the reactor. The volatile liquid evaporates in the hot fluidized bed to form a gas which mixes with the fluidizing gas. The evaporated liquid exits the top of the reactor as part of the recycle gas and passes through the heat exchange part of the recycle loop. The evaporated liquid condenses in the heat exchanger and is then feed to the reactor as a volatile liquid.
In practice, in the gas phase commercial copolymers are made using monomers having 2 to 8 carbon atoms because of the lower concentrations possible in the reactor for alpha-olefins with greater carbon numbers. Traditional Ziegler catalysts are not particularly efficient or effective at incorporating the alpha-olefin comonomers having greater numbers of carbon atoms into the polymer. To date, highly active and highly efficient supported metallocene catalysts, which do have high rates of alpha-olefin comonomer incorporation into the polymer, have not been demonstrated.
Up to now, supported metallocene catalysts useful for producing polyolefin homopolymers and copolymers in gas phase and slurry processes have had reported catalyst efficiencies of less than 50,000,000 grams polymer/mole catalyst/hour for Zr based catalysts and 24,000,000 grams polymer/mole catalyst/hour for Ti based catalysts except when used with exceptionally high ratios of cocatalyst to catalyst. A variety of metallocene loadings and catalyst concentrations have been reported with no obvious trends. Indeed, due to the nonuniformity in the conventions used to report the data, and imprecision in the definitions of various terms in the disclosures, there appears to be little relationship between the use of various classes of metallocene complexes or any optimal ranges for the various process variables employed.
There is a need for a supported olefin polymerization catalyst system that can be used more efficiently, effectively and economically to polymerize olefins or to copolymerize ethylene or propylene with higher alpha-olefins having from about 3 to about 20 carbon atoms in gas phase and slurry processes.
We have made the surprising discovery that, for supported metallocene catalysts with a formulation having less than 25 xcexcmol metallocene/gram support and a relatively low cocatalyst/catalyst ratio, the measured catalyst efficiencies are invariably greater than 50,000,000 grams polymer/mole catalyst/hour for Zr based catalysts and 24,000,000 grams polymer/mole catalyst/hour for Ti based catalysts and, in a preferred embodiment can be greater than about 50,000,000 grams polymer/mole catalyst/hour for Ti based catalysts. This phenomenon is independent of the choice of metallocene, the choice of cocatalyst, the choice of support and the method of preparation of the support or the method of preparation of the formulated catalyst or the method of activation of the catalyst or the method of injection of the formulated catalyst into the reactor.
In one embodiment, this invention provides a process for the polymerization of an olefin monomer, or of an olefin monomer and one or more comonomers, to produce a polymer, the process carried out in a polymerization reactor in the presence of a supported olefin polymerization catalyst system produced from catalyst components comprising:
1) a support material component comprising one or more dehydrated support materials;
2) a metallocene complex component comprising one or more metallocene complexes used in a total loading range of from about 0.1 to about 25 xcexcmol of metallocene complex/gram of support material component;
3) an activator component comprising one or more activators used in a range of molar ratios of total moles of activator to total moles of metallocene complex of from about 0.5 to about 2.5;
where the catalyst system is used at a catalyst concentration in the range of from about 0.01xc3x9710xe2x88x926 to about 6xc3x9710xe2x88x926 moles of active catalyst/mole of monomer, and a catalyst efficiency results that is at least 2.4xc3x97107 g polymer/mol catalyst hour.
In another embodiment, this invention provides a process for the polymerization of an olefin monomer, or of an olefin monomer and one or more comonomers, to produce a polymer, the process carried out in a polymerization reactor in the presence of a supported olefin polymerization catalyst system produced from catalyst components comprising:
1) a support material component comprising one or more dehydrated support materials;
2) a metallocene complex component comprising one or more metallocene complexes all of which have as a central metal Ti used in a total loading range of from about 0.1 to about 25 xcexcmol of metallocene complex/gram of support material component;
3) an activator component comprising one or more activators used in a range of molar ratios of total moles of activator to total moles of metallocene complex of from about 0.5 to about 2.5;
where a catalyst efficiency results that is at least 2.4xc3x97107 g polymer/mol catalyst/hour.
In another embodiment, this invention provides a process for the polymerization of an olefin monomer, or of an olefin monomer and one or more comonomers, to produce a polymer, the process carried out in a polymerization reactor in the presence of a supported olefin polymerization catalyst system produced from catalyst components comprising:
1) a support material component comprising one or more dehydrated support materials;
2) a metallocene complex component comprising one or more metallocene complexes having as a central metal Ti in which the formal oxidation state is +2 used in a total loading range of from about 0.1 to about 25 xcexcmol of metallocene complex/gram of support material component;
3) an activator component;
where a catalyst efficiency results that is at least 2.4xc3x97107 g polymer/mol catalyst/hour.
Also provided by this invention is a supported olefin polymerization catalyst system produced from catalyst components comprising:
1) a support material componentcomprising one or more dehydrated support materials;
2) a metallocene complex component; and
3) an activator component;
where the metallocene complex component is used in a loading range of from about 0.1 to about 25 xcexcmol/gram of support material component, the cocatalyst or activator component is used in a range of molar ratios to the metallocene complex component of from about 0.5 to about 2.5 and, when the catalyst system is used in a reactor to polymerize one or more olefin monomers to produce a polymer, the catalyst system is used at a catalyst concentration in the range of about 0.01xc3x9710xe2x88x926 to about 6xc3x9710xe2x88x926 moles of active catalyst/mole of monomer, and a catalyst efficiency results that is at least 2.4xc3x97107 g polymer/mole of catalyst/hour.
An important aspect of the process of this invention is that it provides a balance of various catalyst system elements with polymerization process elements, the results of which is that the catalyst efficiency of the catalyst system is improved and can be maximized. Accordingly, in one aspect of this invention, there is provided a process for maximizing the efficiency of a catalyst system for the polymerization of an olefin monomer, or of an olefin monomer and one or more comonomers, to produce a polymer, the process carried out in a polymerization reactor in the presence of a supported olefin polymerization catalyst system produced from catalyst components comprising:
1) a support material componentcomprising one or more dehydrated support materials;
2) a metallocene complex component; and
3) an activator component;
wherein the metallocene complex component is used in a loading range, in terms of mass of metallocene complex component relative to the mass of support material component, the activator component is used in a range of molar ratios of the activator component to the metallocene complex component, and the catalyst system is used in a range of catalyst concentrations, in a balanced manner to maximize the catalyst efficiency in terms of mass of polymer produced per mass of catalyst per hour.
In another embodiment this invention provides a catalyst system comprising:
a) a metallocene component comprising one or more metallocene complexes supported on individual metallocene supports or a common metallocene support; and
b) a cocatalyst component comprising one or more cocatalysts or activators supported on individual cocatalyst supports or a common cocatalyst support, where at least one of the cocatalysts or activators is a non-alumoxane nonionic cocatalyst or activator.
Table 1 gives data disclosed in various references, all of which are hereby incorporated by reference, related to the use of supported metallocene catalysts useful for producing polyolefin homo- and copolymers in gas phase, slurry and solution processes. Despite a variety of metallocene loadings ranging from 2 to 625 xcexcmol/gram silica, and cocatalyst/catalyst ratios from 1.2 to greater than 400, and in reactor catalyst concentrations (where the reactor is defined as the combined volumes of the polymerization zone and freeboard for a fluid bed reactor or the combined volumes of the polymerization zone and head space for a slurry or solution reactor) from 0.2xc3x9710-6 to more than 200xc3x9710xe2x88x926 mole catalyst/mole monomer, the reported catalyst efficiencies are less than 24,000,000 grams polymer/mole catalyst/hour, except when a very high catalyst loading and/or a very high ratio of cocatalyst to catalyst has been used. From these references no apparent trends of interrelationship between these factors is evident.
All references herein to elements or metals belonging to a certain Group refer to the Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1989. Also any reference to the Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups.
This invention provides a process for the polymerization of an olefin monomer, or of an olefin monomer and one or more comonomers, to produce a polymer, the process carried out in a polymerization reactor in the presence of a supported olefin polymerization catalyst system produced from catalyst components comprising: 1) a metallocene complex component; 2) an activator component; and 3) a support material component.
Suitable metallocene complexes for use in the metallocene complex component of this invention include any compound or complex of a metal of Groups 3-10 of the Periodic Table of the Elements capable of being activated to olefin insertion and polymerization by the presence of an activator or through the use of a method of activation. These metallocene complexes may be weak catalysts prior to activation, or they may exhibit no catalytic activity prior to activation. In the discussion herein, metallocene complexes subject to activation in the catalyst system of this invention may be referred to simply as catalysts. Examples include Group 10 diimine derivatives corresponding to the formula: 
M* is Ni(II) or Pd(II);
K is hydrocarbyl;
Ar* is an aryl group, especially 2,6-diisopropylphenyl, 2,6-dimethylphenyl, 2,6-di-t-butylphenyl, or 2,6-diphenylphenyl; and
T independently each occurrence is selected from the group consisting of hydrogen, C1-4 alkyl or phenyl, or two T groups together with the two carbon moieties form a fused ring system, especially a 1,8-naphthanediyl group.
Certain of the foregoing catalysts are disclosed by M. Brookhart, et al., in J. Am. Chem. Soc., 118, 267-268 (1996) and J. Am. Chem. Soc., 117, 6414-6415 (1995), as being active polymerization catalysts especially for polymerization of xcex1-olefins, either alone or in combination with polar comonomers such as alkyl acrylates and alkyl methacrylates. In an embodiment of the present invention it has now been discovered that the foregoing catalysts also are effective for use in the polymerization of vinyl chloride monomer.
Additional catalysts include derivatives of Group 3, 4, 5, 6, 7, 8, or 9, or Lanthanide metals which are in the +2, +3, or +4 formal oxidation state. Preferred compounds include metal complexes containing from 1 to 3 xcfx80-bonded anionic or neutral ligand groups, which may be cyclic or noncyclic delocalized xcfx80-bonded anionic ligand groups. Exemplary of such xcfx80-bonded anionic ligand groups are conjugated or nonconjugated, cyclic or noncyclic dienyl groups, allyl groups, boratabenzene groups, and arene groups. By the term xe2x80x9cxcfx80-bondedxe2x80x9d is meant that the ligand group is bonded to the transition metal by means of a xcfx80 bond.
Each atom in the delocalized xcfx80-bonded group may independently be substituted with a radical selected from the group consisting of hydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from Group 14 of the Periodic Table of the Elements, and such hydrocarbyl- or hydrocarbyl-substituted metalloid radicals further substituted with a Group 15 or 16 heteroatom containing moiety. Included within the term xe2x80x9chydrocarbylxe2x80x9d are C1-20 straight, branched and cyclic alkyl radicals, C6-20 aromatic radicals, C720 alkyl-substituted aromatic radicals, and C7-20 aryl-substituted alkyl radicals. In addition two or more such radicals may together form a fused ring system, a hydrogenated fused ring system, or a metallocycle with the metal. Suitable hydrocarbyl-substituted organo-metalloid radicals include mono-, di- and tri-substituted organometalloid radicals of Group 14 elements wherein each of the hydrocarbyl groups contains from 1 to 20 carbon atoms. Examples of suitable hydrocarbyl-substituted organometalloid radicals include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, and trimethylgermyl groups. Examples of Group 15 or 16 heteroatom containing moieties include amine, phosphine, ether, or thioether moieties or divalent derivatives thereof, for example amide, phosphide, hydrocarbyloxy, hydrocarbylthio or thioether groups bonded to the transition metal or Lanthanide metal, and bonded to the hydrocarbyl group or to the hydrocarbyl-substituted metalloid-containing group.
Examples of suitable anionic, delocalized xcfx80-bonded groups include cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl, silacyclohexadienyl, allyl, dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups, and boratabenzene groups, as well as C1-10 hydrocarbyl-substituted or C1-10 hydrocarbyl-substituted silyl substituted derivatives thereof. Preferred anionic delocalized xcfx80-bonded groups are cyclopentadienyl, pentamethylcyclopentadienyl, tetramethylcyclopentadienyl, trimethylsilylcyclopentadienyl, indenyl, 2,3-dimethylindenyl, fluorenyl, 2-methylindenyl, 2-methyl-4-phenylindenyl, tetrahydrofluorenyl, octahydrofluorenyl, tetrahydroindenyl, cyclohexadienyl, and silacyclohexadienyl.
The boratabenzenes are anionic ligands which are boron containing analogues to benzene. They are previously known in the art having been described by G. Herberich, et al., in Organometallics, 14,1, 471-480 (1995). Preferred boratabenzenes correspond to the formula: 
wherein Rxe2x80x3 is selected from the group consisting of hydrocarbyl, silyl, or germyl, said Rxe2x80x3 having up to 20 nonhydrogen atoms.
A suitable class of catalysts are transition metal complexes corresponding to the formula:
LlMXmXxe2x80x2nXxe2x80x3p, or a dimer thereof
wherein:
L is an anionic, delocalized, xcfx80-bonded group that is bound to M, containing up to 50 nonhydrogen atoms, optionally two L groups may be joined together forming a bridged structure, and further optionally one L may be bound to X, or even further optionally one L may be bound to Xxe2x80x2;
M is a metal of Group 4 of the Periodic Table of the Elements in the +2, +3 or +4 formal oxidation state;
X is an optional, divalent substituent of up to 50 nonhydrogen atoms that together with L forms a metallocycle with M;
Xxe2x80x2 is an optional neutral Lewis base having up to 20 nonhydrogen atoms;
Xxe2x80x3 each occurrence is a monovalent, anionic moiety having up to 40 nonhydrogen atoms, optionally, two Xxe2x80x3 groups may be covalently bound together forming a divalent dianionic moiety having both valences bound to M, or, optionally 2 Xxe2x80x3 groups may be covalently bound together to form a neutral, conjugated or nonconjugated diene that is xcfx80-bonded to M (whereupon M is in the +2 oxidation state), or further optionally one or more Xxe2x80x3 and one or more Xxe2x80x2 groups may be bonded together thereby forming a moiety that is both covalently bound to M and coordinated thereto by means of Lewis base functionality;
1 is 0, 1 or 2;
m is 0 or 1;
n is a number from 0 to 3;
p is an integer from 0 to 3; and
the sum, 1+m+p, is equal to the formal oxidation state of M, except when 2 Xxe2x80x3 groups together form a neutral conjugated or nonconjugated diene that is xcfx80-bonded to M, in which case the sum 1+m is equal to the formal oxidation state of M.
Preferred complexes include those containing either one or two L groups. The latter complexes include those containing a bridging group linking the two L groups. Preferred bridging groups are those corresponding to the formula (ER*2)x wherein E is silicon, germanium, tin, or carbon, R* independently each occurrence is hydrogen or a group selected from silyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R* having up to 30 carbon or silicon atoms, and x is 1 to 8. Preferably, R* independently each occurrence is methyl, ethyl, propyl, benzyl, tert-butyl, phenyl, methoxy, ethoxy or phenoxy. Preferably, x is 1or 2.
Examples of the complexes containing two L groups are compounds corresponding to the formula: 
wherein:
M is zirconium, zirconium or hafnium, preferably zirconium or hafnium, in the +2 or +4 formal oxidation state;
R3 in each occurrence independently is selected from the group consisting of hydrogen, hydrocarbyl, hydrocarbyloxy, silyl, germyl, cyano, halo and combinations thereof, (especially, hydrocarbyloxysilyl, halocarbyl, and halohydrocarbyl) said R3 having up to 20 nonhydrogen atoms, or adjacent R3 groups together form a divalent derivative (that is, a hydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fused ring system, and
Xxe2x80x3 independently each occurrence is an anionic ligand group of up to 40 nonhydrogen atoms, or two Xxe2x80x3 groups together form a divalent anionic ligand group of up to 40 nonhydrogen atoms or together are a conjugated diene having from 4 to 30 nonhydrogen atoms forming a xcfx80-complex with M, whereupon M is in the +2 formal oxidation state, and
R*, E and x are as previously defined.
The foregoing metal complexes are especially suited for the preparation of polymers having stereoregular molecular structure. In such capacity it is preferred that the complex possesses Cs symmetry or possesses a chiral, stereorigid structure. Examples of the first type are compounds possessing different delocalized xcfx80-bonded systems, such as one cyclopentadienyl group and one fluorenyl group. Similar systems based on Ti(IV) or Zr(IV) were disclosed for preparation of syndiotactic olefin polymers in Ewen, et al., J. Am. Chem. Soc. 110, 6255-6256 (1980). Examples of chiral structures include rac bis-indenyl complexes. Similar systems based on Ti(IV) or Zr(IV) were disclosed for preparation of isotactic olefin polymers in Wild et al., J. Organomet. Chem., 232, 233-47, (1982).
Exemplary bridged ligands containing two xcfx80-bonded groups are: (dimethylsilyl-bis(cyclopentadienyl)), (methylphenylsilyl-bis(methylcyclopentadienyl)), (diphenylsilyl-bis(ethylcyclopentadienyl)), (dimethylsilyl-bis(t-butylcyclopentadienyl)), (dimethylsilyl-bis(tetramethylcyclopentadienyl)), (dimethylsilyl-bis(indenyl)), (dimethylsilyl-bis(tetrahydroindenyl)), (dimethylsilyl-bis(fluorenyl)), (dimethylsilyl-bis(tetrahydrofluorenyl)), (dimethylsilyl-bis(2-methyl-4-phenylindenyl)), (dimethylsilyl-bis(2-methylindenyl)), (dimethylsilyl-cyclopentadienyl-fluorenyl), (dimethylsilyl-cyclopentadienyl-octahydrofluorenyl), (dimethylsilyl-cyclopentadienyl-tetrahydrofluorenyl), (1,1,2,2-tetramethyl-1,2-disilyl-bis-cyclopentadienyl), 1,2-bis(cyclopentadienyl)ethane, and (isopropylidene-cyclopentadienyl-fluorenyl).
Preferred Xxe2x80x3 groups are selected from hydride, hydrocarbyl, hydrocarbyloxy, halo, amido, siloxy, phosphido, silyl, germyl, halohydrocarbyl, halosilyl, silylhydrocarbyl and aminohydrocarbyl groups, or two Xxe2x80x3 groups together form a divalent derivative of a conjugated diene or else together they form a neutral, xcfx80-bonded, conjugated diene. Most preferred Xxe2x80x3 groups are C1-20 hydrocarbyl groups.
A further class of metal complexes utilized in the present invention corresponds to the preceding formula LlMXmXxe2x80x2nXxe2x80x3p, or a dimer thereof, wherein X is a divalent substituent of up to 50 nonhydrogen atoms that together with L forms a metallocycle with M, or wherein one Xxe2x80x2 is bound to both L and M.
Preferred divalent X substituents include groups containing up to 30 nonhydrogen atoms comprising at least one atom that is oxygen, sulfur, boron or a member of Group 14 of the Periodic Table of the Elements directly attached to the delocalized xcfx80-bonded group, and a different atom, selected from the group consisting of nitrogen, phosphorus, oxygen or sulfur that is covalently bonded to M.
A preferred class of such Group 4 metal coordination complexes used according to the present invention corresponds to the formula: 
wherein:
M is titanium or zirconium in the +2 or +4 formal oxidation state;
R3 in each occurrence independently is selected from the group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof, said R3 having up to 20 nonhydrogen atoms, or adjacent R3 groups together form a divalent derivative (that is, a hydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fused ring system,
each Xxe2x80x3 is a hydride, hydrocarbyl, hydrocarbyloxy, siloxy, amido, phosphido, halo or silyl group, said group having up to 20 nonhydrogen atoms, or two Xxe2x80x3 groups together form a neutral C5-30 conjugated diene or a divalent derivative thereof;
Y is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR*xe2x80x94, xe2x80x94PR*xe2x80x94, and
Z is SiR*2, CR*2, SiR*2SiR*2, CR*2CR*2, CR*xe2x95x90CR*, CR*2SiR*2, or GeR*2, wherein R* is as previously defined.
A further preferred class of Group 4 metal coordination complexes used according to the present invention wherein one Xxe2x80x2 (illustrated by Zxe2x80x94Yxe2x80x2) is bound to both L and M corresponds to the formula: 
wherein:
M is titanium in the +3 formal oxidation state;
R3 each occurrence is independently selected from the group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof, said R3 having up to 20 nonbydrogen atoms, or adjacent R3 groups together form a divalent derivative (that is a hydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fused ring system;
each Xxe2x80x3 is a hydrocarbyl, hydrocarbyloxy, hydride, siloxy, amido, phosphido, halo or silyl group, said group having up to 20 nonhydrogen atoms;
Yxe2x80x2 is xe2x80x94OR*, xe2x80x94SR*, NR*2, xe2x80x94PR*2;
Z is SiR*2,CR*2, SiR*2SiR*2, CR*2CR*2, CR*xe2x95x90CR*, CR*2SiR*2, or GeR*2, wherein R* is as previously defined; and
n is a number from 0 to 3.
An especially preferred group of transition metal complexes for use in the catalysts of this invention are those disclosed in U.S. Pat. No. 5,470,993, incorporated herein by reference, which correspond to the formula: 
wherein:
M is titanium or zirconium in the +2 formal oxidation state;
L is a group containing a cyclic, delocalized anionic, xcfx80-system through which the group is bound to M, and which group is also bound to Z;
Z is a moiety bound to M via "sgr"-bond, comprising boron, and the members of Group 14 of the Periodic Table of the Elements, and also comprising an element selected from the groups consisting of an element selected from the groups consisting of nitrogen, phosphorus, sulfur and oxygen, said moiety having up to 60 nonhydrogen atoms; and
X is a neutral, conjugated or nonconjugated diene, optionally substituted with one or more groups selected from hydrocarbyl or trimethylsilyl groups, said X having up to 40 carbon atoms and forming a xcfx80-complex with M.
Illustrative Group 4 metal complexes that may be employed in the practice of the present invention include:
cyclopentadienyltitaniumtrimethyl,
cyclopentadienyltitaniumtriethyl, cyclopentadienyltitaniumtriisopropyl,
cyclopentadienyltitaniumtriphenyl,
methylcyclopentadienyltitaniumtribenzyl,
pentamethylcyclopentadienyltitanium-2,4-dimethylpentadienyl,
cyclopentadienyltitanium-2,4-dimethylpentadienylotriethylphosphine,
cyclopentadienyltitanium-2,4-dimethylpentadienyletrimethylphosphine,
cyclopentadienyltitaniumdimethylmethoxide, cyclopentadienyltitaniumdimethylchloride,
pentamethylcyclopentadienyltitaniumtrimethyl,
indenyltitaniumtrimethyl,
2-methylindenyltitaniumtriethyl,
2-phenylindenyltitaniumtripropyl,
3-methylindenyltitaniumtriphenyl,
tetrahydroindenyltitaniumtribenzyl, tetramethylcyclopentadienyltitaniumtriisopropyl,
pentamethylcyclopentadienyltitaniumtribenzyl,
pentamthylcyclopentadienyltitanumdimethyhnethoxide,
pentamethylcyclopentadienyltitaniumdimethylchloride,
bis(xcex75-2,4-dimethylpentadienyl)titanium,
bis(xcex75-3-methylpentadienyl)titaniumotrimethylphosphine,
bis(xcex75-1,5-bis(trimethylsilyl)pentadienyl)titaniumetriethylphosphine,
octahydrofluorenyltitaniumtrimethyl,
tetrahydroindenyltitaniumtrimethyl,
tetrahydrofluorenyltitaniumtrimethyl,
(tert-butylamido)(1,1-dimethyl-2,3,4,9,10xcex7-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,
(tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-xcex7-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,
(cyclohexylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium dibenzyl,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium dimethyl,
(teit-butylamido)(tetramethyl-xcex75-cyclopentadienyl)1,2-ethanediyltitanium dimethyl,
(tert-butylamido)(tetramethyl-xcex75-indenyl)dimethylsilanetitanium dimethyl,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilane titanium (III) 2-(dimethylamino)benzyl,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (III) allyl,
(isopropylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitaniwn (III) 2,4-dimethylpentadienyl,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (II) 1,4-diphenyl-1,3-butadiene,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyI)dimethylsilanetitanium (II) 1,3-pentadiene,
(tert-butylamido)(2-methylindenyl)dimethylsitanetitanium (II) 1,4-diphenyl-1,3-butadiene,
(cyclodocedylamindo)(2-methylindenyl)dimethylsilanetitanium (II) 2,4-hexadiene,
(tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV) 2,3-dimethyl-1,3-butadiene,
(anilido)(2-methylindenyl)dimethylsilanetitanium (IV) isoprene,
(ethylamido)(2-methylindenyl)dimethylsilanetitanium (III) 2-(dimethylamino)benzyl,
(tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV) 2,3-dimethyl-1,3-butadiene,
(cyclohexylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (III) 2-(dimethylamino)benzyl, (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV) dimethyl(methylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV) dibenzyl (anilido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV) 1,3-butadiene,
(tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II) 1,3-pentadiene,
(tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II) 1,4-diphenyl-1,3-butadiene,
(anilido)(2-methylindenyl)dimethylsilanetitanium (II)1,3-pentadiene,
(tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV) dimethyl,
(tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (III) 2-(dimethylamino)benzyl,
(tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II) 1,4diphenyl-1,3-butadiene,
(tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II) 1,3-pentadiene,
(cyclohexylamido)(2-methyl4-phenylindenyl)dimethylsilanetitanium (II) 2,4-hexadiene,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyldimethylsilanetitanium (IV) 1,3-butadiene,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (III) 2-(dimethylamino)benzyl
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (IV) isoprene,
(tert-pentylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (II) 1,4-dibenzyl-1,3-butadiene,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl(dimethylsilanetitanium (II) 2,4-hexadiene,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilanetitanium (II) 3-methyl-1,3-pentadiene,
(tert-butylamido)(2,4-dimethylpentadienyl)dimethylsilanetitaniumdimethyl,
(tert-butylamido)(6,6-dimethylcyclohexadienyl)dimethylsilanetitaniumdimethyl,
(tert-octylamido)(1,1-dimethyl-2,3,4,9,10-xcex7-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl,
(anilido)(1,1,2,3-tetramethyl-2,3,4,9,10-xcex7-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)methylphenyl-silanetitanium (IV) dimethyl,
(tert-butylamido)(tetramethyl-xcex75-cyclopentadienyl)methylphenyl-silanetitanium (II) 1,4-diphenyl-1,3-butadiene,
1-(tert-butylamido)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (IV) dimethyl,
1-(tert-butylamido)-2-(tetramethyl-xcex75-cyclopentadienyI)ethanediyl-titanium (II) 1,4-diphenyl-1,3-butadiene,
1-(dimethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (II) dimethyl,
1-(dimethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (III) diallyl,
1-(dimethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (III) dibenzyl,
1-(diisobutylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (III) dimethyl,
1-(diisopropylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (III) dimethyl,
1-(methylphenylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)ethanediyl-titanium (III) dimethyl,
(dimethylamino)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilyltitanium (III) dimethyl,
(diethylamino)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilyltitanium (III) diallyl,
(dimethylamino)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilyltitanium (III) dibenzyl,
(diisobutylamino)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilyl-titaniun (III) dimethyl,
(diisopropylamino)(tetramethyl-xcex75-cyclopentadienyl)dimethylsilyl-titanium (III) methylphenyl,
(methylphenylamino)(tetramethyl-5-cyclopentadienyl)dimethylsilyl-titanium (III) dimethyl,
(1-methylethoxy)(tetramethyl-xcex75-cyclopcntadienyl)dimethylsilane-titanium (III) dimethyl,
1-(dimethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetranethyldisilyltitanium (III) dimethyl,
1-(dimethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetramethyldisilyltitanium (III) diallyl,
1-(diethylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetramethyldisilyltitanium (III) dibenzyl,
1-(diisobutylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetramethyldisilyltitanium (III) dimethyl,
1-(diisopropylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetramethyldisilyltitanium (III) dimethyl,
1-(methylphenylamino)-2-(tetramethyl-xcex75-cyclopentadienyl)-1,1,2,2-tetramethyldisilyltitanium (III) dimethyl,
1-(diethylamiino)-2-(2,3-dimethyl-xcex75-indenyl)ethanediyltitanium (III) dimethyl,
1-(dimethylamino)-2-(2-methyl-xcex75-indenyl)ethanediyltitanium (II) diallyl,
1-(dimethylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)ethanediyltitanium (III) dibenzyl,
1-(diisobutylamino)-2-xcex75-indenyl)ethanediyltitanium (III) dimethyl,
1-(diisopropylamino)-2-xcex75-cyclopentadienyl)ethanediyltitanium (II) dimethyl,
1-(methylphenylamino)-2-xcex75-tetrahydroindenyl)ethanediyltitanium (III) dimethyl,
(dimethylamino)(xcex75-tetrahydrofluorenyl)dimethylsilyltitanium (III) dimethyl,
(diethylamino)(xcex75-octahydrofluorenyl)dimethylsilyltitanium (III) diallyl,
(dimethylamino)(2,3,4,6-tetramethyl-xcex75-indenyl)dimethylsilyltitanium (III) dibenzyl,
(diisobutylamino)(2,3,4,6-tetramethyl-xcex75-indenyl)diimethylsilyl-titanium (III) dimethyl,
(diisopropylamino)(2,3,4,6-tetramethyl-xcex75-indenyl)dimethylsilyl-titanium (III) dimethyl,
(methylphenylamino)(2,3,4,6-tetramethyl-xcex75-indenyl)dimethylsilyi-titanium (III) dimethyl,
(1-methylethoxy)(2,3,4,6-tetramethyl-xcex75-indenyl)dimethylsilanetitanium (III) dimethyl,
1-(dimethylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)-1,2,2-tetramethyldisilyltitanium (III) dimethyl,
1-(dimethylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)-1,1,2,2-tetramethyldisilyltitanium (III) diallyl,
1-(diethylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)-1,1,2,2-tetramethyldisilyltitanium (III) dibenzyl,
1-(diisobutylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)- 1,1,2,2-tetramethyldisilyltitanium (III) dimethyl,
1-(diisopropylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)-1,1,2,2-tetramethyldisilyltitanium (III) dimethyl, and
1-(methylphenylamino)-2-(2,3,4,6-tetramethyl-xcex75-indenyl)-1,1,2,2-tetramethyldisilyltitanium (III) dimethyl.
Complexes containing two L groups including bridged complexes suitable for use in the present invention include:
bis(cyclopentadienyl)zirconiumdimethyl,
bis(butylcyclopentadienyl)zirconium dibenzyl,
bis(cyclopentadienyl)zirconium methyl benzyl, bis(cyclopentadienyl)zirconium methyl phenyl, bis(methylcyclopentadienyl)zirconiumdiphenyl,
bis(cyclopentadienyl)titanium-allyl,
bis(butylcyclopentadienyl)zirconiumiethylmethoxide,
bis(cyclopentadienyl)zirconiunmethylchloride,
bis(pentamethylcyclopentadienyl)zirconiumdimethyl,
bis(pentamethylcyclopentadienyl)titaniumdimethyl,
bis(indenyl)zirconiumdimethyl, indenylfluorenylzirconiumdimethyl,
bis(2-phenylindenyl)zirconiummethyl(2-(dimethylamino)benzyl),
bis(indenyl)zirconium methyltrimethylsilyl,
bis(tetrahydroindenyl)zirconium methyltrimethylsilyl,
bis(trimethylsilylcyclopentadienyl)zirconiummethylbenzyl,
bis(pentamethylcyclopentadienyl)zirconiumdibenzyl,
bis(pentamethylcyclopentadienyl)zirconiummethylmethoxide,
bis(tetramethylcyclopentadienyl)zirconiummethylchloride,
bis(methylethylcyclopentadienyl)zirconiumdimethyl,
bis(ethylbutylcyclopentadienyl)zirconium dibenyl,
bis(t-butylcyclopentadienyl)zirconiumdimethyl,
bis(ethyltetramethylcyclopentadienyl)zirconiumdimethyl,
bis(methylpropylcyclopentadienyl)zirconium dibenzyl,
bis(bis(trimethylsily)clopentadienyl)zirconium dibenzyl,
dimethethylsilyl-bis(cyclopentadienyl)zirconiumdimethyl,
dimethylsilyl-bis(tetramethylcyclopentadienyl)titanium-(III) allyl
dimethylsilyl-bis(t-butylcyclopentadienyl)zirconiumdichloride, dimethylsilyl-bis(n-butylcyclopentadienyl)zirconiumdichloride,
methylene-bis(tetramethylcyclopentadienyl)titanium(III) 2-(dimethylamio)benzyl,
methylene-bis(n-butylcyclopentadienyl)titanium(III) 2-(dimethylaminomethyl)phenyl,
dimethylsiyly-bis(indenyl)zirconiumbenzylchloride,
dimethylsilyl-bis(2-methylindenyl)zirconiumdimethyl,
dimethylsilyl-bis(2-methyl-4-phenylindenyl)zirconiumdimethyl,
dimethylsilyl-bis(2-methylindenyl)zirconium(II) 1,4-diphenyl-1,3-butadiene,
dimethylsilyl-bis(2-methyl4-phenylindenyl)zirconium (II) 1,4-diphenyl-1,3-butadiene,
dimethylsilyl-bis(tetrahydroindenyl)zirconium(II) 1,4-diphenyl-1,3-butadiene,
dimethylsilyl-bis(fluorenyl)zirconiunmuethylchloride,
dimethylsilyl-bis(tetrahydrofluorenyl)zirconium bis(trimethylsilylmethyl),
(isopropylidene)(cyclopentadienyl)(fluorenyl)zirconiumdibenzyl, and
dimethylsilyl(tetramethylcyclopentadienyl)(fluorenyl)zirconium dimethyl.
(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7xcex7)-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)dimethyltitanium
(N(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7a-xcex7)-3-(1-piperidinyl) 1H -1-yl)silanaminato(2-)-N)dimethyltitanium
((2-(dimethylamino)phenyl)methyl)(1,1-dimethyl-N-phenyl-1-((1,2,3,3a,7a-xcex7)-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)titanium
(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7a-xcex7)-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)((1,2,3,4-xcex7)-2,4-hexadiene)titanium
(1,1xe2x80x2-(xcex74-1,3-butadiene-1,4-diyl)bis(benzene))(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7a-xcex7)-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)titanium
((2-(dimethylamino)phenyl)methyl)(N-(1,1-dimethylethyl)- 1,1-dimethyl-1-((1,2,3,3a,7-xcex7)-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)titanium
(N-cyclohexyl-1,1-dimethyl-1-((1,2,3,3a,7a-xcex7)-5-phenyl-3-(1-pyrrolidinyl)-1H-inden-1-yl)silanaminato(2-)-N)dimethyltitanium
(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7-xcex7)-3-(dimethylamino)-1H-inden-1-yl)silanaminato(2-)-N)dimethyltitanium
(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,3a,7a-xcex7)-3-methoxy-1H-inden-1-yl)silanaminato(2-)-N)dimethyltitanium
(N-(1,1-dimethylethyl)-2-((1,2,3,3a,7-xcex7)-2-methyl-3-(1-pyrrolidinyl)-1H-inden-1-yl)-ethanaminato(2-)-N)dimethyltitanium
(1,1xe2x80x2-(xcex74-1,3-butadiene-1,4-diyl)bis(benzene))(N-(1,1-dimethylethyl)-1,1-dimethyl-1-((1,2,3,4,5-xcex7)-2,4,5-trimethyl-3-(1-pyrrolidinyl)-2,4-cyclopentadien-1-yl)silanaminato(2-)N)titanium
Especially preferred bis-Cp complexes for use in the catalysts useful in this invention are the bridged bis-Cp complexes of EP 676,421 which correspond to the formula: 
wherein
Cp1, Cp2 are independently a substituted or unsubstituted indenyl or hydrogenated indenyl group;
Y is a univalent anionic ligand, or Y2 is a diene;
M is zirconium, titanium or hafnium; and
Z is a bridging group comprising an alkylene group having 1 to 20 carbon atoms or a dialkylsilyl or dialkylgermyl group, or alkylphosphine or alkylarine radical.
Another class of preferred metal complexes for use in the present invention correspond to the formula (I): 
where
M is titanium, zirconium or hafnium in the +2, +3 or +4 formal oxidation state:
R is an aryl ligand or a halo-, silyl-, alkyl-, cycloalkyl-, dihydrocarbylamino-, hydrocarbyloxy-, or hydrocarbyleneamino-, substituted derivative thereof, said Rxe2x80x2 having from 6 to 40 nonhydrogen atoms;
Z is a divalent moiety, or a moiety comprising one "sgr"-bond and a neutral two electron pair able to form a coordinate-covalent bond to M, said Z comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen;
X is a monovalent anionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, xcfx80-bound ligand groups;
Xxe2x80x2 independently each occurrence is a neutral Lewis base ligating compound having up to 20 atoms;
Xxe2x80x3 is a divalent anionic ligand group having up to 60 atoms;
p is zero, 1, 2, or 3;
q is zero, 1 or 2; and
r is zero or 1.
The above complexes may exist in pure form or as a mixture with other complexes, in the form of a solvated adduct, optionally in a solvent, especially an organic liquid, as well as in the form of a dimer or chelated derivative thereof, wherein the chelating agent is an organic material.
Another class of preferred metal complexes for use in the present invention correspond to the formula: 
where
M is a metal from one of Groups 3 to 13 of the Periodic Table of the Elements, the lanthanides or actinides, which is in the +2, +3 or +4 formal oxidation state and which is xcfx80-bonded to one cyclopentadienyl group (Cp) which is a cyclic, delocalized, xcfx80-bound ligand group having 5 substituents: RA; (RB)j-T where j is zero, 1 or 2; RC; RD and Z; where RA, RB, RC and RD are R groups; and where
T is a heteroatom which is covalently bonded to the Cp ring, and to RB when j is 1 or 2, and when j is 0, T is F, Cl, Br, or I; when j is 1, T is O or S, or N or P and RB has a double bond to T; when j is 2, T is N or P; and where
RB independently each occurrence is hydrogen, or, is a group having from 1 to 80 nonhydrogen atoms which is hydrocarbyl, hydrocarbylsilyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilylhydrocarbyl, hydrocarbylamino, di(hydrocarbyl)amino, hydrocarbyloxy, each RB optionally being substituted with one or more groups which independently each occurrence is hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms; and each of RA, RC and RD is hydrogen, or is a group having from 1 to 80 nonhydrogen atoms which is hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl, hydrocarbylsilylhydrocarbyl, each RA, RC or RD optionally being substituted with one or more groups which independently each occurrence is hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms; or, optionally, two or more of RA, RB, RC and RD are covalently linked with each other to form one or more fused rings or ring systems having from 1 to 80 nonhydrogen atoms for each R group, the one or more fused rings or ring systems being unsubstituted or substituted with one or more groups which independently each occurrence are hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarby, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substitutcd hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms,
Z is a divalent moiety bound to both Cp and M via "sgr"-bonds, where Z comprises boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprises nitrogen, phosphorus, sulfur or oxygen;
X is an anionic or dianionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, xcfx80-bound ligand groups;
Xxe2x80x2 independently each occurrence is a neutral Lewis base ligating compound having up to 20 atoms;
p is zero, 1 or 2, and is two less than the formal oxidation state of M, when X is an anionic ligand; when X is a dianionic ligand group, p is 1; and
q is zero, 1 or 2.
Another class of preferred metal complexes for use in the present invention corresponding to the formula: 
where
M is a metal from one of Groups 3 to 13 of the Periodic Table of the Elements, the lanthanides or actinides, which is in the +2, +3 or +4 formal oxidation state and which is xcfx80-bonded to one cyclopentadienyl group (Cp) which is a cyclic, delocalized, xcfx80-bound ligand group having 5 substituents: (RA)j-T where j is zero, 1 or 2; RB; RC; RD and Z; where RA, RB, RC and RD are R groups; and where
T is a heteroatom which is covalently bonded to the Cp ring, and to RA when j is 1 or 2, and when j is 0, T is F, Cl, Br, or I; when j is 1, T is G or S, or N or P and RA has a double bond to T; when j is 2, T is N or P; and where
RA independently each occurrence is hydrogen, or, is a group having from 1 to 80 nonhydrogen atoms which is hydrocarbyl, hydrocarbylsilyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilylhydrocarbyl, hydrocarbylamino, di(hydrocarbyl)amino, hydrocarbyloxy, each RA optionally being substituted with one or more groups which independently each occurrence is hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms; and each of RB, RC and RD is hydrogen, or is a group having from 1 to 80 nonhydrogen atoms which is hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl, hydrocarbylsilylhydrocarbyl, each RB, RC or RD optionally being substituted with one or more groups which independently each occurrence is hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms; or, optionally, two or more of RA, RB, RC and RD are covalently linked with each other to form one or more fused rings or ring systems having from 1 to 80 nonhydrogen atoms for each R group, the one or more fused rings or ring systems being unsubstituted or substituted with one or more groups which independently each occurrence are hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino, di(hydrocarbylsilyl)amino, hydrocarbylamino, di(hydrocarbyl)amino, di(hydrocarbyl)phosphino, hydrocarbylsulfido, hydrocarbyl, halo-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, hydrocarbylamino-substituted hydrocarbyl, hydrocarbylsilyl or hydrocarbylsilylhydrocarbyl having from 1 to 20 nonhydrogen atoms, or a noninterfering group having from 1 to 20 nonhydrogen atoms;
Z is a divalent moiety bound to both Cp and M via "sgr"-bonds, where Z comprises boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprises nitrogen, phosphorus, sulfur or oxygen;
X is an anionic or dianionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, xcfx80-bound ligand groups;
Xxe2x80x2 independently each occurrence is a neutral Lewis base ligating compound having up to 20 atoms;
p is zero, 1 or 2, and is two less than the formal oxidation state of M, when X is an anionic ligand, when X is a dianionic ligand group, p is 1; and
q is zero, 1 or 2.
Constrained geometry metal complexes and methods for their preparation are disclosed in U.S. application Ser. No. 545,403, filed Jul. 3, 1990 (EP-A416,815), U.S. application Ser. No. 547,718, filed Jul. 3, 1990 (EP-A-468,65I), U.S. application Ser. No. 702,475, filed May 20, 1991 (EP-A-514,828), U.S. application Ser. No. 876,268, filed May 1,1992 (EP-A-520,732); and U.S. application Ser. No. 8,003, filed Jan. 21, 1993 (WO 93/19104), as well as U.S. Pat. Nos. 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380; and WO 95/00526. The teachings of all of the foregoing patents or the corresponding U.S. patent applications are hereby incorporated by reference.
The metallocene complex component may be produced with a single metallocene complex, or, in alternative embodiment, it may be produced with two or more metallocene complexes, or it may be produced with at least one metallocene complex and at least one nonmetallocene complex.
Other catalysts, especially catalysts containing other Group 4 metals, will, of course, be apparent to those skilled in the art.
The supported olefin polymerization catalyst system comprises an activator component which is used to activate the metallocene complex component of the catalyst system. In a preferred embodiment of this invention, the activator component comprises a cocatalyst, especially an activating cocatalyst.
Alternatively, in another embodiment, the complexes are rendered catalytically active by the use of an activating technique or method.
Suitable activating cocatalysts for use herein include polymeric or oligomeric alumoxanes, especially methylalumoxane, triisobutyl aluminum-modified methylalumoxane, or diisobutylalumoxane; strong Lewis acids, such as C1-30 hydrocarbyl substituted Group 13 compounds, especially tri(hydrocarbyl)aluminum- or tri(hydrocarbyl)boron-compounds and halogenated derivatives thereof, having from 1 to 1 0 carbons in each hydrocarbyl or halogenated hydrocarbyl group, especially tris(pentafluorophenyl)borane; and nonpolymeric, inert, compatible, noncoordinating, ion forming compounds (including the use of such compounds under oxidizing conditions). A suitable activating technique is bulk electrolysis (explained in more detail hereinafter). Combinations of the foregoing activating cocatalysts and techniques may also be employed if desired. The foregoing activating cocatalysts and activating techniques have been previously taught with respect to different metal complexes in the following references: EP-A-277,003; U.S. Pat. Nos. 5,153,157; 5,064,802; EP-A-468,651 (equivalent to U.S. Ser. No. 07/547,718); EP-A-520,732 (equivalent to U.S. Ser. No. 07/876,268); and U.S. Pat, No. 5,350,723; teachings of which are hereby incorporated by reference.
Suitable nonpolymeric, inert, compatible, noncoordinating, ion forming compounds useful as cocatalysts in one embodiment of the present invention comprise a cation which is a Bronsted acid capable of donating a proton, and a compatible, noncoordinating, anion, Axe2x88x92. Preferred anions are those containing a single coordination complex comprising a charge-bearing metal or metalloid core which anion is capable of balancing the charge of the active catalyst species (the metal cation) which is formed when the two components are combined. Also, said anion can be displaced by olefinic, diolefinic and acetylenically unsaturated compounds or other neutral Lewis bases such as ethers or nitrites. Suitable metals include, but are not limited to, aluminum, gold and platinum. Suitable metalloids include, but are not limited to, boron, phosphorus, and silicon. Compounds containing anions which comprise coordination complexes containing a single metal or metalloid atom are well known and many, particularly such compounds containing a single boron atom in the anion portion, are available commercially.
Preferably such cocatalysts may be represented by the following general formula:
(L*xe2x80x94H)+dAdxe2x88x92
wherein:
L* is a neutral Lewis base;
(L*xe2x80x94H)+ is a Bronsted acid;
Adxe2x88x92 is a noncoordinating, compatible anion having a charge of dxe2x88x92, and d is an integer from 1 to 3.
More preferably d is one, that is, Adxe2x88x92is Axe2x80x94.
Highly preferably, Axe2x88x92 corresponds to the formula: [BQ4]xe2x88x92wherein:
B is boron in the +3 formal oxidation state; and
Q independently each occurrence is selected from hydride, dialkylarido, halide, alkoxide, aryloxide, hydrocarbyl, halocarbyl, and halo-substituted-hydrocarbyl radicals, said Q having up to 20 carbons with the proviso that in not more than one occurrence is Q halide.
In a more highly preferred embodiment, Q is a fluorinated C1-20 hydrocarbyl group, most preferably, a fluorinated aryl group, especially, pentafluorophenyl.
Illustrative, but not limiting, examples of ion forming compounds comprising proton donatable cations which may be used as activating cocatalysts in the preparation of the catalysts of this invention are tri-substituted ammonium salts such as:
trimethylammonium tetraphenylborate,
methyldioctadecylammonium tetraphenylborate,
triethylammonium tetraphenylborate,
tripropylammonium tetraphenylborate,
tri(n-butyl)ammonium tetraphenylborate,
metbyltetradecyloctadecylammonium tetraphenylborate,
N,N-dimethylanilinium tetraphenylborate,
N,N-diethylanilinium tetraphenylborate,
N,N-dimethyl(2,4,6-trimethylanilinium) tetraphenylborate,
trimethylammonium tetrakis(penta-fluorophenyl)borate,
triethylammonium tetrakis(pentafluorophenyl)borate,
tripropylammonium tetrakis(pentafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate,
tri(sec-butyl)ammonium tetrakis(pentafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-diethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-dimethyl(2,4,6-trimethylanilinium) tetrakis(pentafluorophenyl)borate,
trimethylammoniun tetrakis(2,3,4,6-tetrafluorophenyl)borate,
triethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate,
tripropylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate,
tri(n-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate,
dimethyl(t-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate,
N,N-diethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate, and
N,N-dimethyl-(2,4,6-trimethylanilinium) tetrakis-(2,3,4,6-tetrafluoro-phenyl)borate.
Dialkyl ammonium salts such as:
di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate, and
dicyclohexylammonium tetrakis(pentafluorophenyl)borate.
Tri-substituted phosphonium salts such as:
triphenylphosphonium tetrakis(pentafluorophenyl)borate,
tri(o-tolyl)phosphonium tetrakis(pentafluorophenyl)borate, and
tri(2,6dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate.
Preferred are tetrakis(pentafluorophenyl)borate salts of long chain alkyl mono- and disubstituted ammonium complexes, especially C14-C20 alkyl ammonium complexes, especially methyldi(octadecyl)ammonium tetrakis(pentafluorophenyl)borate and methyldi(tetradecyl)ammonium tetrakis(pentafluorophenyl)borate.
An especially preferred group of activating cocatalysts is tris(pentafluorophenyl)borane, Nxe2x80x94R3,Nxe2x80x94R4 anilinium tetrakis(pentafluorophenyl)borate where R3 and R4 independently each occurrence are substituted or unsubstituted saturated hydrocarbyl groups having from 1 to 8 carbon atoms, (R1R2NHCH3)+(C6H4OH)B(C6F5)3xe2x88x92, or (R1R2NHCH3)+B(C6F5)4xe2x88x92, where R1 and R2 independently each occurrence are substituted or unsubstituted saturated hydrocarbyl groups having from 12 to 30 carbon atoms.
Another suitable ion forming, activating cocatalyst comprises a salt of a cationic oxidizing agent and a noncoordinating, compatible anion represented by the formula:
xe2x80x83(Oxe+)d(Adxe2x88x92)e
wherein:
Oxe+ is a cationic oxidizing agent having charge e+;
e is an integer from 1 to 3; and
Adxe2x88x92, and d are as previously defined.
Examples of cationic oxidizing agents include: ferrocenium, hydrocarbyl-substituted ferrocenium, Ag+, or Pb+2. Preferred embodiments of Adxe2x88x92 are those anions previously defined with respect to the Bronsted acid containing activating cocatalysts, especially tetrakis(pentafluorophenyl )borate.
Another suitable ion forming, activating cocatalyst comprises a compound which is a salt of a carbenium ion or silylium ion and a noncoordinating, compatible anion represented by the formula:
(copyright)+Axe2x88x92
wherein:
(copyright)+ is a C1-20 carbenium ion or silylium ion; and
Axe2x88x92 is as previously defined.
A preferred carbenium ion is the trityl cation, that is triphenylcarbenium. A preferred silylium ion is triphenylsilylium.
Ionic compounds (a) suitable for use in the present invention and their methods of preparation are described in U.S. patent application Ser. No. 08/610,647, filed Mar. 4, 1996 (corresponding to WO-96/28480) which is incorporated herein by reference. The term used in the anion a.2) of the ionic compound xe2x80x9cat least one substituent comprising an active hydrogen moietyxe2x80x9d means in the present application a substituent comprising a hydrogen atom bonded to an oxygen, sulphur, nitrogen or phosphorous atom.
In the anion a.2), the at least one substituent comprising an active hydrogen moiety preferably corresponds to the formula
Gq(Txe2x80x94H)r(I)
wherein G is a polyvalent hydrocarbon radical, the group (Txe2x80x94H) is a radical wherein T comprises O, S, NR, or PR, the O, S, N, or P atom of which is bonded to hydrogen atom H, wherein R is a hydrocarbyl radical, a trihydrocarbyl silyl radical, a trihydrocarbyl germyl radical, or hydrogen, H is hydrogen, q is 0 or 1, and preferably 1, and r is an integer from 1 to 3, preferably 1. Polyvalent hydrocarbon radical G has r+1 valencies, one valency being associated with a metal or metalloid of the Groups 5-15 of the Periodic Table of the Elements in the anion, the other r valencies of G being attached to r groups (Txe2x80x94H). Preferred examples of G include di- or trivalent hydrocarbon radicals such as: alkylene, arylene, aralkylene, or alkarylene radicals containing from 1 to 20 carbon atoms, more preferably from 2 to 12 carbon atoms. Suitable examples of divalent hydrocarbon radicals G include phenylene, biphenylene, naphthylene, methylene, ethylene, 1,3-propylene, 1,4-butylene, phenylrhethylene (xe2x80x94C6H4xe2x80x94CH2xe2x80x94). The polyvalent hydrocarbyl portion G may be further substituted with radicals that do not negatively impact the effect to be achieved by the present invention.
Preferred examples of such noninterfering substituents are alkyl, aryl, alkyl- or aryl-substituted silyl and germyl radicals, and fluoro substituents.
The group (Txe2x80x94H) in the previous formula may be an xe2x80x94OH, xe2x80x94SH, xe2x80x94NRH, or xe2x80x94PRH group, wherein R preferably is a C1-18, preferably a C1-12, hydrocarbyl radical or hydrogen, and H is hydrogen. Preferred R groups are alkyls, cycloalkyls, aryls, arylalkyls, or alkylaryls of 1 to 18 carbon atoms, more preferably those of 1 to 12 carbon atoms. Alternatively, the group (Txe2x80x94H) comprises an xe2x80x94OH, xe2x80x94SH, xe2x80x94NRH, or xe2x80x94PRH group which are part of a larger functional moiety such as, for example, C(O)xe2x80x94OH, C(S)xe2x80x94OH, C(S)xe2x80x94SH, C(O)xe2x80x94SH, C(O)xe2x80x94NRH, C(S)xe2x80x94NRH, and C(O)xe2x80x94PRH, and C(S)xe2x80x94PRH. Most preferably, the group (Txe2x80x94H) is a hydroxy group, xe2x80x94OH, or an amino group, xe2x80x94NRH.
Very preferred substituents Gq(TH) in anion a.2) include hydroxy- and amino- substituted aryl, aralkyl, alkaryl or alkyl groups, and most preferred are the hydroxyphenyls, especially the 3- and 4-hydroxyphenyl groups and 2,4-dihydroxyphenyl, hydroxytolyls, hydroxybenzyls (hydroxymethylphenyl), hydroxybiphenyls, hydroxynaphthyls, hydroxycyclohexyls, hydroxymethyls, and hydroxypropyls, and the corresponding amino-substituted groups, especially those substituted with xe2x80x94NRH wherein R is an alkyl or aryl radical having from 1 to 10 carbon atoms, such as for example methyl, ethyl, propyl, i-propyl, n-, i-, or t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl, phenyl, benzyl, tolyl, xylyl, naphthyl, and biphenyl.
The anion a.2) may further comprise a single Group 5-15 element or a plurality of Group 5-15 elements but is preferably a single coordination complex comprising a charge-bearing metal or metalloid core. Preferred anions a.2) are those containing a single coordination complex comprising a charge-bearing metal or metalloid core carrying the at least one substituent containing an active hydrogen moiety. Suitable metals for the anions of ionic compounds (a) include, but are not limited to, aluminum, gold, platinum and the like. Suitable metalloids include, but are not limited to elements of groups 13, 14, and 15, of the Periodic Table of the Elements, preferably are, boron, phosphorus, and silicon. Ionic compounds which contain anions comprising a coordination complex containing a single boron atom and one or more substituents comprising an active hydrogen moiety are preferred. Examples of suitable anions comprising a single Group 5-15 element are disclosed in EP 0 277 004 and examples of those having a plurality of Group 5-15 elements are disclosed in EP 0 277 003, with the proviso that at least one of the subsituents in the anions described therein is substituted by a substituent comprising an active hydrogen moiety, preferably Gq(Txe2x80x94H)r.
Preferably, anions a.2) may be represented by a single coordination complex of the following general Formula (II):
[Mxe2x80x2m+Qn(Gq(Txe2x80x94H)r)z]dxe2x88x92xe2x80x83xe2x80x83(II)
wherein:
Mxe2x80x2 is a metal or metalloid selected from Groups 5-15 of the Periodic Table of the Elements;
Q independently in each occurrence is selected from the group consisting of hydride, dihydrocarbylamido, preferably dialkylamido, halide, hydrocarbyloxide, preferably alkoxide and aryloxide, hydrocarbyl, and substituted-hydrocarbyl radicals, including halo-substituted hydrocarbyl radicals, and hydrocarbyl- and halohydrocarbyl-substituted organo-metalloid radicals, the hydrocarbyl portion in each of these groups preferably having from 1 to 20 carbons, with the proviso that in not more than one occurrence is Q halide;
G is a polyvalent hydrocarbon radical having r+1 valencies, and preferably a divalent hydrocarbon radical, bonded to Mxe2x80x2 and r groups (Txe2x80x94H);
the group (Txe2x80x94H) is a radical wherein T comprises O, S, NR, or PR, the O, S, N, or P atom of which is bonded to hydrogen atom H, wherein R is a hydrocarbon radical, trihydrocarbyl silyl radical, a trihydrocarbyl germyl radical, or hydrogen;
m is an integer from 1 to 7, preferably 3;
n is an integer from 0 to 7, preferably 3;
q is an integer 0 or 1, preferably 1;
r is an integer from 1 to 3, preferably 1;
z is an integer from 1 to 8, preferably 1 or 2;
d is an integer from 1 to 7, preferably 1; and
n+zxe2x88x92m=d.
When q is 0 and polyvalent hydrocarbon radical G is not present, T is bound to Mxe2x80x2. Preferred boron-containing anions a.2) which are particularly useful in this invention may be represented by the following general Formula (III):
[BQ4xe2x88x92zxe2x80x2(Gq(Txe2x80x94H)r)zxe2x80x2]dxe2x88x92xe2x80x83xe2x80x83(III)
wherein:
B is boron in a valence state of 3;
zxe2x80x2 is an integer from 1-4, preferably 1 or 2, most preferably 1;
d is 1; and
Q, G, T, H, q, and r are as defined for Formula (II). Preferably, zxe2x80x2 is 1 or 2, q is 1, and r is 1.
Illustrative, but not limiting, examples of anions a.2) of ionic compounds to be used in the present invention are boron-containing anions such as:
triphenyl(hydroxyphenyl)borate, triphenyl(2,4-dihydroxyphenyl)borate, tri(p-tolyl)(hydroxyphenyl)borate,
tris-(pentafluorophenyl)(hydroxyphenyl)borate, tris-(2,4-dimethylphenyl)(hydroxyphenyl)borate,
tris-(3,5-dimethylphenyl)(hydroxyphenyl)borate,
tris-(3,5-di-trifluoromethyl-phenyl)(hydroxyphenyl)borate, tris(pentafluorophenyl)(2-hydroxyethyl)borate, tris(pentafluorophenyl)(4-hydroxybutyl)borate,
tris(pentafluoropheny)(4-hydroxycyclobexyl)borate, tris(pentafluorophenyl)(4-(4xe2x80x2-hydroxyphenyl)phenyl)borate, tris(pentafluorophenyl)(6-hydroxy-2-naphthyl)borate, and the like.
Further preferred anions a.2) include those containing two substituents containing an active hydrogen moiety, for example: diphenyldi(hydroxyphenyl)borate, diphenyldi(2,4-dihydroxyphenyl)borate, di(p-tolyl) di(hydroxyphenyl)borate, di(pentafluorophenyl)di-(hydroxyphenyl)boratc, di(2,4-dimethylphenyl) di(hydroxyphenyl)borate, di (3,5-dimethylphenyl) di(hydroxyphenyl)borate, di (3,5-di-trifluoromethylphenyl) di(hydroxyphenyl)borate, di(pentafluorophenyl) di(2-hydroxyethyl)borate, di(pentafluorophenyl) di(4-hydroxybutyl)borate, di(pentafluorophenyl) di(4-hydroxycyclohexyl)borate, di(pentafluorophenyl) di(4-(4xe2x80x2-hydroxyphenyl)phenyl)borate, di(pentafluorophenyl) di(6-hydroxy-2-naphthyl)borate, and the like.
Other preferred anions are those above mentioned borates wherein the hydroxy functionality is replaced by an amino NHR functionality wherein R preferably is methyl, ethyl, or t-butyl. A highly preferred anion a.2) is tris(pentafluorophenyl)(4-hydroxyphenyl) borate.
The cationic portion a. 1) of the ionic compound is preferably selected from the group consisting of Bronsted acidic cations, especially ammonium and phosphonium cations or sulfonium cations, carbonium cations, silylium cations, oxonium cations, and cationic oxidizing agents. The cations a.1) and the anions a.2) are used in such ratios as to give a neutral ionic compound.
Bronsted acidic cations may be represented by the following general formula:
(Lxe2x80x94H)+
wherein:
L is a neutral Lewis base, preferably a nitrogen, phosphorus, oxygen, or sulfur containing Lewis base; and (Lxe2x80x94H)+ is a Bronsted acid.
Illustrative, but not limiting, examples of Bronsted acidic cations are trihydrocarbyl- and preferably trialkyl-substituted ammonium cations such as triethylammonium, tripropylammonium, tri(n-butyl)ammonium, trimethylammonium, tri(n-butyl)ammonium, and tri(n-octyl)ammonium. Also suitable are N,N-dialkyl anilinium cations such as N,N-dimethylanilinium, N,N-diethyl-anilinium, N,N-2,4,6-pentamethylanilinium, N,N-dimethylbenzylammonium and the like; dialkylammonium cations such as di-(i-propyl)ammonium, dicyclohexylammonium and the like; and triarylphosphonium cations such as triphenylphosphonium, tri(methyl-phenyl)phosphonium, tri(dimethylphenyl)phosphonium, dimethylsulphonium, diethylsulphonium, and diphenylsulphonium.
In a highly preferred embodiment, the Bronsted acidic cation a.1) may be represented by the following general formula:
[L*xe2x80x94H]+,
wherein:
L* is a nitrogen, oxygen, sulfur or phosphorus containing Lewis base which comprises at least one relatively long chain alkyl group. Preferably such L* groups contain from one to three C10-40 alkyl groups with a total of from 12 to 100 carbons, more preferably two C10-40 alkyl groups and from 21 to 90 total carbons. It is understood that the cation may comprise a mixture of alkyl groups of differing lengths. For example, one suitable cation is the protonated ammonium salt derived from the commercially available long chain amine comprising a mixture of two C14, C16 or C18 alkyl groups and one methyl group. Such amines are available from Witco Corp., under the trade name Kemamine(trademark) T970 1, and from Akzo-Nobel under the trade name Armeen(trademark) M2HT. These preferred cations are described in U.S. provisional application No. 60/014284, filed Mar. 27, 1996, which is incorporated herein by reference. Ionic compounds (a) comprising the cation [L*xe2x80x94H]+ can be easily prepared by subjecting an ionic compound comprising the cation [Lxe2x80x94H]+ and the anion a.2), as prepared in U.S. patent application Ser. No. 08/610,647, filed Mar. 4, 1996 (corresponding to WO-96/28480), to a cation exchange reaction with a [L*xe2x80x94H]+ salt.
Illustrative, but not limiting examples of the highly preferred cations a.1) of the ionic compound (a) arc tri-substituted ammonium salts such as:
decyldi(methyl)ammonium, dodecyldi(methyl)ammonium,
tetradecyldi(methyl)ammonium, hexaadecyldi(methyl)ammonium,
octadecyldi(methyl)ammonium, eicosyldi(methyl)ammonium,
methyldi(decyl)ammonium, methyldi(dodecyl)ammonium,
methyldi(tetradecyl)ammonium, methyldi(hexadecyl)ammonium,
methyldi(octadecyl)ammonium, methyldi(eicosyl)ammonium, tridecylammonium,
tridodecylammonium, tritetradecylammonium, trihexadecylammonium,
trioctadecylammonium, trieicosylammonium, decyldi(n-butyl)ammonium, dodecyldi(n-butyl)ammmonium, octadecyldi(n-butyl)ammonium,
N,N-didodecylanilinium, N-methyl-N-dodecylanilinium,
N,N-di(octadecyl)(2,4,6-trimethylanilinium), cyclohexyldi(dodecyl)ammonium, and methyldi(dodecyl)ammonium.
Suitable similarly substituted sulfonium or phosphonium cations such as, di(decyl)sulfonium, (n-butyl)dodecylsulfonium, tridecylphosphonium, di(octadecyl)methylphosphonium, and tri(tetradecyl)phosphonium, may also be named.
Preferred ionic compounds (b) are di(octadecyl)methylammonium tris(pentafluorophenyl)(hydroxyphenyl)borate, octadecyl dimethylammonium tris(pentafluorophenyl)(hydroxyphenyl)borate and di(octadecyl) (n-butyl)ammonium tris(pentafluorophenyl)(hydroxyphenyl)borate, as well as the amino (-NHR) analogues of these compounds wherein the hydroxyphenyl group is replaced by the aminophenyl group.
A second type of suitable cation corresponds to the formula: (copyright)+, wherein (copyright)+ is a stable carbonium or silylium ion containing up to 30 nonhydrogen atoms. Suitable examples of cations include tropyllium, triphenylmethylium, benzene(diazonium). Silylium salts have been previously generically disclosed in J. Chem. Soc. Chem. Comm., 1993, 383-384, as well as Lambert, J. B., et. al., Organometallics, 1994, 13, 2430-2443. Preferred silylium cations are triethylsilylium, and trimethylsilylium and ether substituted adducts thereof.
Another suitable type of cation comprises a cationic oxidizing agent represented by the formula:
Oxe+
wherein Oxe+ is a cationic oxidizing agent having a charge of e+, and e is an integer from 1 to 3.
Examples of cationic oxidizing agents include: ferrocenium, hydrocarbyl-substituted ferrocenium, Ag+, and Pb2+.
In general, the catalyst system can be prepared by combining the catalyst components in any order in a suitable solvent at a temperature within the range from about xe2x88x92100xc2x0 C. to about 300xc2x0 C. or by generating the activated catalyst electrochemically as previously explained, followed by wet or dry deposition and impregnation of the support material component. Alternatively, the metallocene complex component and the activator component may be individually deposited on the support material component in any order, optionally with individual solvent removal and/or drying. The activated catalyst may be separately prepared prior to use by combining the respective components. The catalyst and cocatalyst as well as activated catalyst system generally are sensitive to both moisture and oxygen and should be handled and transferred in an inert atmosphere.
The catalyst system of this invention is produced from catalyst components comprising a support material component. Especially suited support materials for the support material component of the catalyst system include polymers, inorganic oxides, metal halides, prepolymerized polymeric substrates or a mixture thereof. A preferred group of support materials is inorganic oxides and includes silica, alumina, silica-alumina, or a mixture thereof. Other suitable support materials include silica, alumina, silica-alumina, or a mixture thereof which has been modified with TiO2, ZrO2, GeO2, B2O3, or a mixture thereof. Suitable supported catalyst systems are readily prepared by contacting the present metal complexes with the substrate, optionally while subjecting the mixture to heating and/or reduced pressures.
Preferred supports for use in the present invention include highly porous silicas, aluminas, aluminosilicates, and mixtures thereof. The most preferred support material is silica. The support material may be in granular, agglomerated, pelletized, or any other physical form. Suitable materials include, but are not limited to, silicas available from Grace Davison (division of W. R. Grace and Co.) under the designations SD 3216.30, Davison Syloid(trademark) 245, Davison 948 and Davison 952, and from Degussa AG under the designation Aerosil(trademark) 812; and aluminas available from Akzo Chemicals Inc. under the designation Ketzen(trademark) Grade B.
Supports suitable for the present invention preferably have a surface area as determined by nitrogen porosimetry using the B.E.T. method from 10 to about 1000 m2/g, and preferably from about 100 to 600 m2/g. The pore volume of the support, as determined by nitrogen adsorption, advantageously is between 0.1 and 3 cm3/g, preferably from about 0.2 to 2 cm3/g. The average particle size is not critical, but typically is from 0.5 to 500 xcexcm, preferably from 1 to 100 xcexcm.
Both silica and alumina are known to inherently possess small quantities of hydroxyl functionality attached thereto. When used as a support herein, these materials are preferably subjected to a heat treatment and/or chemical treatment to reduce the hydroxyl content thereof. Typical heat treatments are carried out at a temperature from 30xc2x0 C. to 1000xc2x0 C. for a duration of 10 minutes to 50 hours in air or an inert atmosphere or under reduced pressure. Typical chemical treatments include contacting with Lewis acid alkylating agents such as trihydrocarbyl aluminum compounds, trihydrocarbylchlorosilane compounds, trihydrocarbylalkoxysilane compounds or similar agents. Preferred silica or alumina materials for use herein have a surface hydroxyl content that is less than 0.8 mmol of hydroxyl groups per gram of solid support, more preferably less than 0.5 mmol per gram. The hydroxyl content may be determined by adding an excess of dialkyl magnesium to a slurry of the solid support and determining the amount of dialkyl magnesium remaining in solution via known techniques. This method is based on the reaction:
Sxe2x80x94OH+Mg(Alk)2xe2x86x92Sxe2x80x94OMg(Alk)+(Alk)H,
wherein S is the solid support, and Alk is a C1-4 alkyl group.
The support may be unfunctionalized (excepting for hydroxyl groups as previously discussed) or functionalized by treating with a silane or chlorosilane functionalizing agent to attach thereto pendant silane xe2x80x94(Sixe2x80x94R)xe2x95x90, or chlorosilane xe2x80x94(Sixe2x80x94Cl)xe2x95x90 functionality, wherein R is a C1-10 hydrocarbyl group. Suitable functionalizing agents are compounds that react with surface hydroxyl groups of the support or react with the silicon or aluminum of the matrix. Examples of suitable functionalizing agents include phenylsilane, diphenylsilane, methylphenylsilane, dimethylsilane, diethylsilane, chlorofrimethylsilane, hexamethyldisilazane, dichlorosilane, and dichlorodimethylsilane. Techniques for forming such functionalized silica or alumina compounds were previously disclosed in U.S. Pat. Nos. 3,687,920 and 3,879,368, the teachings of which are herein incorporated by reference.
The support may also be treated with an aluminum component selected from an lumoxane or an aluminum compound of the formula AlR3, wherein R independently each occurrence is hydride or R1, and R1 is C1-4 alkyl. Preferably, the aluminum component is selected from the group consisting of aluminoxanes and tris(C1-4 alkyl)aluminum compounds. Most preferred aluminum components are aluminoxanes, trimethylaluminum, triethylaluminum, tri-isobutylaluminum, and mixtures thereof.
Alumoxanes (also referred to as aluminoxanes) are oligomeric or polymeric aluminum oxy compounds containing chains of alternating aluminum and oxygen atoms, whereby the aluminum carries a substituent, preferably an alkyl group. The structure of alumoxane has been believed to be represented by the following general formulae (xe2x80x94Al(R1)xe2x80x94O)mxe2x80x2, for a cyclic alumoxane, and R12Alxe2x80x94O(xe2x80x94Al(R1)xe2x80x94O)mxe2x80x2xe2x80x94AlR12, for a linear compound, wherein R1 is C1-4 alkyl, and mxe2x80x2 is an integer ranging from 1 to about 50, preferably at least about 4. Alumoxanes are typically the reaction products of water and an alkylaluminum compound, which in addition to an alkyl group may contain halide or alkoxide groups. Reacting a mixture of several different alkylaluminum compounds, such as for example trimethylaluminum and tri-isobutylaluminum, with water yields so-called modified or mixed alumoxanes. Preferred alumoxanes are methylalumoxane and methylalumoxane modified with minor amounts of C2-4 alkyl groups, especially isobutyl groups. Alumoxanes generally contain minor to substantial amounts of starting alkylaluminum compound.
Particular techniques for the preparation of alumoxane type compounds by contacting an alkylaluminum compound with an inorganic salt containing water of crystallization are disclosed in U.S. Pat. No. 4,542,119. in a particular preferred embodiment, an alkylaluminum compound is contacted with a regeneratable water-containing substance such as hydrated alumina, silica or other substance. This is disclosed in EP-A-338,044. Thus the alumoxane may be incorporated into the support by reaction of a hydrated alumina or silica material, which has optionally been functionalized with silane, siloxane, hydrocarbyloxysilane, or chlorosilane groups, with a tris(C1-10 alkyl) aluminum compound according to known techniques. For the teachings contained therein the foregoing patents and publications, or their corresponding equivalent United States applications, are hereby incorporated by reference.
The treatment of the support material in order to include optional alumoxane or trialkylaluminum loadings involves contacting the same with an alumoxane or trialkylaluminum compound before, after, or simultaneously with addition of the complex or activated catalyst. Optionally the mixture can also be heated under an inert atmosphere for a period and at a temperature sufficient to fix the alumoxane, trialkylaluminum compound, complex or catalyst system to the support. Optionally, the treated support component containing alumoxane or the trialkylaluminum compound may be subjected to one or more wash steps, using toluene or similar solvent, to remove excess alumoxane, trialkylaluminum, or any other soluble aluminum compound that is not fixed to the support.
Besides contacting the support with alumoxane, the alumoxane may be generated in situ by contacting an unhydrolyzed silica or alumina or a moistened silica or alumina with a trialkyl aluminum compound optionally in the presence of an inert diluent. Such a process is well known in the art, having been disclosed in EP-A-250,600, U.S. Pat. Nos. 4,912,075, and 5,008,228, the teachings of which, or of the corresponding U.S. application, are hereby incorporated by reference. Suitable aliphatic hydrocarbon diluents include pentane, isopentane, hexane, heptane, octane, isooctane, nonane, isononane, decane, cyclohexane, methylcyclohexane and combinations of two or more of such diluents. Suitable aromatic hydrocarbon diluents are benzene, toluene, xylene, and other alkyl or halogen substituted aromatic compounds. Most preferably, the diluent is an aromatic hydrocarbon, especially toluene. After preparation in the foregoing manner the residual hydroxyl content thereof is desirably reduced to a level less than 1.0 meq of OH per gram of support, by any of the previously disclosed techniques.
The cocatalysts of the invention may also be used in combination with a tri(hydrocarbyl)aluminum compound having from 1 to 10 carbons in each hydrocarbyl group, an oligomeric or polymeric alumoxane compound, a di(hydrocarbyl)(hydrocarbyloxy)aluminum compound having from 1 to 10 carbons in each hydrocarbyl or hydrocarbyloxy group, or a mixture of the foregoing compounds, if desired. These aluminum compounds are usefully employed for their beneficial ability to scavenge impurities such as oxygen, water, and aldehydes from the polymerization mixture. Preferred aluminum compounds include C2-6 trialkyl aluminum compounds, especially those wherein the alkyl groups are ethyl, propyl, isopropyl, xcfx80-butyl, isobutyl, pentyl, neopentyl, or isopentyl, and methylalumoxane, modified methylalumoxane and diisobutylalumoxane. The molar ratio of aluminum compound to metal complex is preferably from 10,000:1 to 1:1000, more preferably from 5000:1 to 1:100, most preferably from 1:100 to 100:1.
In one embodiment of this invention the catalyst system is produced so that it contains alumoxane in a nonactivating amount. Alternatively, the catalyst system may be produced so that it is essentially alumoxane-free.
The molar ratio of catalyst/cocatalyst employed ranges from 1:1000 to 10:1 preferably ranges from 1:10 to 10:1, more preferably from 1l:5 to 1:1, most preferably from 1:1.2 to 1:1. Mixtures of the activating cocatalysts of the present invention may also be employed if desired.
In a highly preferred embodiment of this invention, the catalyst system of this invention is prepared so that the activator component, preferably comprising a cocatalyst, is used in a range of molar ratios to the metallocene complex component of from about 0.3 to about 5, preferably from about 0.5 to about 2.5, more preferably from about 1 to about 2, and even more preferably from about 1 to about 1.5.
An important factor in realizing high efficiencies with the catalyst system of this invention is the range of catalyst loadings, that is, the amount of the metallocene complex component based on the molar amount of the central metal of the complex relative to the weight of the support material component. Desirably, the metallocene complex component is used in a loading range of from about 0.1 to about 25 xcexcmol/gram of support material component, preferably, from about 0.3 to about 20 xcexcmol/gram of support material component, more preferably, from about 1 to about 20 xcexcmol/gram of support material component.
In most polymerization reactions the molar ratio of catalyst to polymerizable compounds employed is from 10xe2x88x9212:1 to 10xe2x88x921:1, more preferably from 10xe2x88x9212:1 to 10xe2x88x925:1.
Molecular weight control agents can be used in combination with the present cocatalysts. Examples of such molecular weight control agents include hydrogen, trialkyl aluminum compounds or other known chain transfer agents. Hydrogen may be present in the polymerization reactor used for the polymerization process of this invention, desirably in a hydrogen to monomer molar ratio which is less than 0.05, more desirably less than 0.02, and preferably less than 0.01.
The supported catalysts in any of the processes of this invention, whether gas phase, slurry, or any other polymerization process, may be used to polymerize additional polymerizable monomers including ethylenically unsaturated monomers, acetylenic compounds, conjugated or nonconjugated dienes, polyenes, and mixtures thereof. Preferred monomers include olefins, for example, xcex1-olefins having from 2 to 100,000, preferably from 2 to 30, more preferably from 2 to 8 carbon atoms and combinations of two or more of such xcex1-olefins.
Particularly suitable c-olefins include, for example, ethylene, propylene, 1-butene, 1-pentene, 4-methylpentene-1, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, and C16-C30 xcex1-olefins or combinations thereof, as well as long chain vinyl terminated oligomeric or polymeric reaction products formed during the polymerization. Preferably, the xcex1-olefins are ethylene, propene, 1-butene, 4-methyl-pentene-1,1-hexene, 1-octene, and combinations of ethylene and/or propene with one or more of such other xcex1-olefins. Other preferred monomers include styrene, halo- or alkyl substituted styrenes, tetrafluoroethylene, vinylcyclobutene, vinylcyclohexene, vinylcyclohexane, vinyl chloride, 1,4-hexadiene, dicyclopentadiene, ethylidene norbornene, and 1,7-octadiene. Mixtures of the above-mentioned monomers may also be employed.
A preferred group of olefin comonomers for polymerizations where ethylene is the monomer includes propene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1,7-octadiene, 1,5-hexadiene, 1,4-pentadiene, 1,9-decadiene, ethylidenenorbornene, styrene, or a mixture thereof. For polymerizations wherein propene is the monomer, the preferred comonomers are the same as that immediately previous, but with the inclusion of ethylene instead of propene.
Long chain macromolecular xcex1-olefins can be vinyl terminated polymeric remnants formed in situ during continuous solution polymerization reactions, and in some other polymerization reactions, such as gas phase polymerization reactions. Under suitable process conditions such long chain macromolecular units may be polymerized into the polymer product along with ethylene and other short chain olefin monomers to give small quantities of long chain branching in the resulting polymer.
In general, the polymerization may be accomplished under conditions well known in the prior art for Ziegler-Natta or Kaminsky-Sinn type polymerization reactions. Suspension, solution, slurry, gas phase or high pressure, whether employed in batch or continuous form or other process conditions, may be employed if desired. Examples of such well known polymerization processes are depicted in WO 88/02009, U.S. Pat. Nos. 5,084,534; 5,405,922; 4,588,790; 5,032,652: 4,543,399; 4,564,647; 4.522,987, which are incorporated herein by reference; and elsewhere. Preferred polymerization temperatures are from 0-250xc2x0 C. Preferred polymerization pressures are from atmospheric to 3000 atmospheres.
In a highly desirable embodiment, the processes of this invention are performed in a single reactor, which may have a single reaction vessel or two or more vessels producing essentially the same polyolefin copolymer composition. Thus, in this embodiment, the polymerization processes of this invention do not produce blends, or where more than one reaction vessel is used do not require blending to produce essentially homogeneous polyolefin copolymer compositions. Alternatively, the catalyst system may employ more than one metallocene complex, or even a nonmetallocene component, to produce reactor blends.
In an important aspect of this invention, which contributes to the high catalyst efficiencies obtainable with the catalyst system of this invention, it is desirable that the catalyst system is used at a catalyst concentration in the range of about 0.01xc3x9710xe2x88x926 to about 6xc3x9710xe2x88x926 moles active catalyst/mole monomer, more desirably, at a catalyst concentration in the range of about 0.01xc3x9710xe2x88x926 to about 5.0xc3x9710xe2x88x926 moles active catalyst/mole monomer, preferably, at a catalyst concentration in the range of about 0.02xc3x9710xe2x88x926 to about 3.0xc3x9710xe2x88x926 moles active catalyst/mole monomer, more preferably, at a catalyst concentration in the range of about 0.05xc3x9710xe2x88x926 to about 3.0xc3x9710xe2x88x926 moles active catalyst/mole monomer, and still more preferably, at a catalyst concentration in the range of about 0.1xc3x9710xe2x88x926 to about 3.0xc3x9710xe2x88x926 moles active catalyst/mole monomer. Active catalyst is defined in this context as the central metal of the metallocene complex of the metallocene complex component of the catalyst system.
Use of the catalyst system of this invention in the polymerization process thereof results in a catalyst efficiency that is at least 24,000,000 g polymer/mole catalyst/hour, desirably, at least 48,000,000 g polymer/mole catalyst/hour, more desirably, at least 72,000,000 g polymer/mole catalyst/hour, even better, at least 96,000,000 g polymer/mole catalyst/hour, still better, at least 144,000,000 g polymer/mole catalyst/hour, even better than that, at least 240,000,000 g polymer/mole catalyst/hour, better still, at least 384,000,000 g polymer/mole catalyst/hour. As used in relationship to the term xe2x80x9ccatalyst efficiencyxe2x80x9d, the mass of polymer, in grams, refers to the mass of polymer produced in the polymerization process relative to the mass, in moles, of the active catalyst required per hour. If the catalyst system is employed in one of the alternative methods described herein, the mass of the catalyst system is simply the sum of the masses of the catalyst components.
The polymerization process of this invention may be conducted under those generally useful for slurry polymerization processes. A description of the slurry process can be found in Volume 6 of the Encyclopedia of Polymer Science and Engineering (John Wiley and Sons) pages 472 to 477 (1986).
By conducting the slurry polymerization under appropriately controlled reaction conditions, the polymer being formed around the solid catalyst system is not melted or dissolved during the polymerization reaction, but maintains a discrete form, which, preferably, is a granular or powdery form during the reaction.
When a polymerization reaction is conducted under slurry process conditions, the polymerization pressure is generally from 1 to 100 atm, preferably from 3 to 30 atm, and the polymerization temperature is generally from 20 to 115xc2x0 C. preferably from 50 to 105xc2x0 C. However, the upper limit of the polymerization temperature is a temperature above which the polymer produced does not maintain its discrete state, and this varies depending on the type and density of the polymer produced and the type of diluent used.
As a diluent to be used for slurry polymerization, typical inert aliphatic or aromatic hydrocarbon solvents can be suitably used, including xylene, benzene, toluene, isobutane, isopentane, heptane, hexane and octane. Hexane, isobutane and isopentane are especially preferred.
In producing a polymer by the process of this invention under slurry conditions, the molecular weight can be controlled by changing the concentration of hydrogen in the reaction system or by changing the polymerization temperature, as described in EP 69951, DE 3127133.2, and U.S. Pat. No. 4,542,199 which are hereby incorporated herein by reference.
The process of the present invention can be employed to advantage in the gas phase polymerization and copolymerization of olefins. Gas phase processes for the polymerization of olefins, especially the homopolymerization and copolymerization of ethylene and propylene, and the copolymerization of ethylene with higher xcex1-olefins such as, for example, 1-butene, 1-hexene, 4-methyl-1-pentene, are well known in the art.
The gas phase process employed can be, for example, of the type which employs a mechanically stirred bed or a gas fluidized bed as the polymerization reaction zone. Preferred is the process wherein the polymerization reaction is carried out in a vertical cylindrical polymerization reactor containing a fluidized bed of polymer particles supported above a perforated plate, fluidization grid, by a flow of fluidization gas.
The gas employed to fluidize the bed comprises the monomer or monomers to be polymerized, and also serves as a heat exchange medium to remove the heat of reaction from the bed. The hot gases emerge from the top of the reactor, normally via a tranquilization zone, also known as a velocity reduction zone, having a wider diameter than the fluidized bed and wherein fine particles entrained in the gas stream have an opportunity to gravitate back into the bed. It can also be advantageous to use a cyclone to remove ultra-fine particles from the hot gas stream. The gas is then normally recycled to the bed by means of a blower or compressor and one or more heat exchangers to strip the gas of the heat of polymerization.
A preferred method of cooling the bed, in addition to the cooling provided by the cooled recycle gas, is to feed a volatile liquid to the bed to provide an evaporative cooling effect. The volatile liquid employed in this case can be, for example, a volatile inert liquid, for example, a saturated hydrocarbon having about 3 to about 8, preferably 4 to 6, carbon atoms. In the case that the monomer or comonomer itself is a volatile liquid, or can be condensed to provide such a liquid, this can suitably be fed to the bed to provide an evaporative cooling effect. Examples of olefin monomers which can be employed in this manner are olefins containing about three to about eight, preferably three to six carbon atoms. The volatile liquid evaporates in the hot fluidized bed to form gas which mixes with the fluidizing gas. If the volatile liquid is a monomer or comonomer, it will undergo some polymerization in the bed. The evaporated liquid then emerges from the reactor as part of the hot recycle gas, and enters the compression/heat exchange part of the recycle loop. The recycle gas is cooled in the heat exchanger and, if the temperature to which the gas is cooled is below the dew point, liquid will precipitate from the gas. This liquid is desirably recycled continuously to the fluidized bed. It is possible to recycle the precipitated liquid to the bed as liquid droplets carried in the recycle gas stream. This type of process is described, for example in EP 89691; U.S. Pat. No. 4,543,399; WO 94/25495 and U.S. Pat. No. 5,352,749, which are hereby incorporated by reference. A particularly preferred method of recycling the liquid to the bed is to separate the liquid from the recycle gas stream and to reinject this liquid directly into the bed, preferably using a method which generates fine droplets of the liquid within the bed. This type of process is described in BP Chemicals"" WO 94/28032, which is hereby incorporated by reference.
The polymerization reaction occurring in the gas fluidized bed is catalyzed by the continuous or semi-continuous addition of the catalyst components of the catalyst system or of the catalyst system as a whole. In a highly desirable method of operation, the catalyst components are produced outside the reactor, the process comprising:
1) depositing one or more metallocene complexes on individual metallocene support portions of the support material component or on a common metallocene support to form one or more individually supported metallocene complex components;
2) depositing one or more cocatalysts on individual cocatalyst support portions of the support material component or on a common cocatalyst support to form one or more individually supported cocatalyst components; and
3) combining together in any order one or more of the metallocene components from 1) and the cocatalyst components from 2) to form the catalyst system prior to introduction of the catalyst system into the reactor; or
4) introducing one or more of the individually supported metallocene components from 1) and the individually supported cocatalyst components from 2) into the reactor individually.
The polymer is produced directly in the fluidized bed by catalyzed copolymerization of the monomer and one or more comonomers on the fluidized particles of catalyst, supported catalyst or prepolymer within the bed. Start-up of the polymerization reaction is achieved using a bed of preformed polymer particles, preferably similar to the target polyolefin, and conditioning the bed by drying with inert gas or nitrogen prior to introducing the catalyst, the monomer(s) and any other gases which it is desired to have in the recycle gas stream, such as a diluent gas, hydrogen chain transfer agent, or an inert condensable gas when operating in gas phase condensing mode. The produced polymer is discharged continuously or discontinuously from the fluidized bed as desired. Such processes are used commercially on a large scale for the manufacture of high density polyethylene (HDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE) and polypropylene.
The gas phase processes suitable for the practice of this invention are preferably continuous processes which provide for the continuous supply of reactants to the reaction zone of the reactor and the removal of products from the reaction zone of the reactor, thereby providing a steady-state environment on the macro scale in the reaction zone of the reactor.
Typically, the fluidized bed of the gas phase process is operated at temperatures greater than 50xc2x0 C., preferably, greater than about 60xc2x0 C. and from about 60xc2x0 C. to about 110xc2x0 C., more preferably, greater than about 70xc2x0 C. and from about 70xc2x0 C. to about 110xc2x0 C., even more preferably, greater than about 80xc2x0 C.
Typically the molar ratio of comonomer to monomer used in the polymerization depends upon the desired density for the composition being produced and is about 0.5 or less. Desirably, where the polymerization is a copolymerization of ethylene or propylene as the monomer and of one or more xcex1-olefin comonomers, the process of this invention employs a comonomer to monomer molar ratio which is less than 0.1, preferably less than 0.05, and more preferably less than 0.01.
For many polymerizations where it is desirable to use hydrogen as a chain transfer agent, it is desirable that the polymerization reactor contain hydrogen in a hydrogen to monomer molar ratio which is less than 0.05, preferably less than 0.02, more preferably less than 0.01.
Desirably, when producing polymers with a density range of from about 0.85 to about 0.98, the comonomer to monomer molar ratio is less than 0.1, the hydrogen to monomer ratio is less than 0.05, and the composition is produced in a reactor with a reaction zone having a temperature of 70xc2x0 C. or higher.
Desirably, when producing polymers with a density range of from about 0.910 to about 0.925, the comonomer to monomer molar ratio is less than 0.02, the hydrogen to monomer ratio is less than 0.02, and the composition is produced in a reactor with a reaction zone having a temperature of 70xc2x0 C. or higher.
Desirably, when producing materials with a density range of from about 0.91 to about 0.93 the comonomer to monomer ratio is less than 0.2, preferably less than 0.05, even more preferably less than 0.02, and may even be less than 0.01. Typically, the ratio of hydrogen to monomer is less than about 0.5, preferably less than 0.2, more preferably less than 0.05, even more preferably less than 0.02 and may even be less than 0.01.
The above-described ranges of process variables are appropriate for the gas phase process of this invention and may be suitable for other processes adaptable to the practice of this invention.
A number of patents and patent applications describe gas phase processes which are adaptable for use in the process of this invention, particularly, U.S. Pat. Nos. 4,588,790. 4,543,399; 5,352,749; 5,436,304; 5,405,922; 5,462,999; 5,461,123; 5,453,471; 5,032,562; 5,028,670; 5,473,028; 5,106,804; 5,556,238; 5,541,270; 5,608,019; 5,616,661; and EP applications 659,773; 692,500; 780,404; 697,420; 628,343; 593,083; 676,421; 683,176; 699,212; 699,213; 721,798; 728,150; 728,151; 728,771; 728,772; 735,058; and PCT Applications WO 94/29032; WO 94/25497; WO 94/25495; WO 94/28032; WO 95/13305; WO 94/26793, WO 95/07942; WO 97/25355; WO 93/11171; WO 95/13305; and WO 95/13306, all of which are hereby incorporated herein by reference.
The skilled artisan will appreciate that the invention disclosed herein may be practiced in the absence of any component which has not been specifically disclosed. The following examples are provided in order to further illustrate the invention and are not to be construed as limiting. Unless stated to the contrary, all parts and percentages are expressed on a weight basis.
Experimental
The polymerization examples which follow were carried out in a 13 liter gas phase reactor having a four inch diameter thirty inch long fluidization zone and an eight inch diameter ten inch long velocity reduction zone which are connected by a transition section having tapered walls. Typical operating ranges are 40 to 1 100xc2x0 C., 250 to 350 psia total pressure and up to 8 hours reaction time. Ethylene, comonomer, hydrogen and nitrogen enter the bottom of the reactor where they pass through a gas distributor plate. The flow of the gas is 2 to 8 times the minimum particle fluidization velocity [Fluidization Engineering, 2nd Ed., D. Kunii and O. Levenspiel, 1991, Butterworth-Heinemann]. Most of the suspended solids disengage in the velocity reduction zone. The reactant gases exit the top of the velocity reduction zone and pass through a dust filter to remove any fines. The gases then pass through a gas booster pump. The polymer is allowed to accumulate in the reactor over the course of the reaction. The total system pressure is kept constant during the reaction by regulating the flow of monomer into the reactor. Polymer is removed from the reactor to a recovery vessel by opening a valve located at the bottom of the fluidization zone. The polymer recovery vessel is kept at a lower pressure than the reactor. The pressures of ethylene, comonomer and hydrogen reported refer to partial pressures.
The mode of reactor operation which was employed is referred to as semi-batch. The catalyst was prepared and loaded into a catalyst injector in an inert atmosphere glovebox. The injector was removed from the glovebox and inserted into the top of the reactor. Appropriate amounts of ethylene, 1-butene, hydrogen and nitrogen were introduced into the reactor to bring the total pressure to 300 psia. The catalyst was then injected and the polymer was usually allowed to form for 30 minutes. The total system pressure was kept constant during the reaction by regulating the flow of monomer into the reactor. After 30 minutes the reactor was emptied and the polymer powder was collected.
Several different silica pretreatment procedures were used. One pretreatment procedure involved first drying approximately 2 grams of the silica under a nitrogen purge at 200xc2x0 C. for several hours. The silica was removed from the drying oven and mixed with a quantity of distilled water equal to 3 weight percent of the silica. The silica containing the water was shaken for about ten minutes to disperse the water evenly and to break up the lumps which formed on addition of the water. The silica was then brought into an inert atmosphere glovebox where in a toluene slurry it was then treated with triethyl aluminum (TEA) in a amount corresponding to an Al/H2O molar ratio of 2/1. The silica was then filtered and washed several times with toluene to remove any residual soluble aluminum compounds which may have resulted during the dehydration step. The supports were then dried under reduced pressure to give a free flowing powder.
A second pretreatment procedure involved first drying approximately 5 grams of the silica under a nitrogen purge at 500xc2x0 C. for 4 hours. The silica was removed from the drying furnace and brought into an inert atmospheric glovebox where in a toluene slurry it was treated with TEA in an amount corresponding to an Al/OH ratio of 1/1. This corresponded to a TEA/silica ratio of 1.2 mmoles TEA/g silica. The silica was then filtered and washed several times with toluene to remove any residual soluble aluminum compounds which may have resulted during the dehydration step. The supports were then dried under reduced pressure to give a free flowing powder.
Preparation of a typical supported catalyst involved first preparing 0.005 M solutions of (xcex75-C5Me4SiMe2NCMe3)Ti(Me2) and of (xcex75-C5Me4SiMe2NCMe3)Ti(s-trans-xcex74-1,4-trans, trans-diphenyl-1,3-butadiene) and of (xcex75-C5Me4SiMe2NCMe3)-Ti(xcex74-C5H8) catalyst and borane ([B(C6F5)3]) cocatalyst in toluene. An appropriate amount (typically 100 to 300 Al) of toluene was added to the silica to pre-wet the support. An appropriate amount of the metallocene catalyst was then added to the silica followed by addition of an appropriate amount of the cocatalyst. The solvents were then removed under vacuum from the agitated slurry to give the catalyst as a free-flowing powder.